[PARISC] Untangle <asm/processor.h> header include mess

asm/processor.h on parisc wants spinlocks for cpuinfo, but
linux/spinlock_types.h needs lockdep, and lockdep wants prefetch.

This leads to a horrible circular dependancy, because <asm/processor.h>
is including something which depends on things which are not defined
until the end of the file.

Kludge around this by moving prefetch related code into <asm/prefetch.h>
and including it before <linux/spinlock_types.h>, however this is just
a temporary solution until this mess can be cleaned up.

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/include/asm-parisc/prefetch.h b/include/asm-parisc/prefetch.h
new file mode 100644
index 000000000000..f5a2e7ae2662
--- /dev/null
+++ b/include/asm-parisc/prefetch.h
@@ -0,0 +1,36 @@
+/*
+ * include/asm-parisc/prefetch.h
+ *
+ * PA 2.0 defines data prefetch instructions on page 6-11 of the Kane book.
+ * In addition, many implementations do hardware prefetching of both
+ * instructions and data.
+ *
+ * PA7300LC (page 14-4 of the ERS) also implements prefetching by a load
+ * to gr0 but not in a way that Linux can use.  If the load would cause an
+ * interruption (eg due to prefetching 0), it is suppressed on PA2.0
+ * processors, but not on 7300LC.
+ *
+ */
+
+#ifndef __ASM_PARISC_PREFETCH_H
+#define __ASM_PARISC_PREFETCH_H
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_PREFETCH
+
+#define ARCH_HAS_PREFETCH
+extern inline void prefetch(const void *addr)
+{
+        __asm__("ldw 0(%0), %%r0" : : "r" (addr));
+}
+
+#define ARCH_HAS_PREFETCHW
+extern inline void prefetchw(const void *addr)
+{
+        __asm__("ldd 0(%0), %%r0" : : "r" (addr));
+}
+
+#endif /* CONFIG_PREFETCH */
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_PARISC_PROCESSOR_H */